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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #415548
Research Project: Science and Technologies for Improving Soil and Water Resources in Agricultural Watersheds

Location: Watershed Physical Processes Research

Title: Long term conservation practice effects on agricultural soil loss from concentrated and distributed sources

Author
item MOMM, HENRIQUE - Middle Tennessee State University
item ELKADIRI, RACHA - Middle Tennessee State University
item Bingner, Ronald - Ron
item MOORE, KATY - Middle Tennessee State University
item Wells, Robert - Rob

Submitted to: Journal of Environmental Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/5/2024
Publication Date: 11/11/2024
Citation: Momm, H.G., El Kadiri, R., Bingner, R.L., Moore, K., Wells, R.R. Long term conservation practice effects on agricultural soil loss from concentrated and distributed sources. Journal of Environmental Management, 371, https://doi.org/10.1016/j.jenvman.2024.123278. 2024.
DOI: https://doi.org/10.1016/j.jenvman.2024.123278

Interpretive Summary: Conservation practices have been recognized as an important mitigation tool to reduce soil loss and sediment transport from agricultural fields. Understanding their combined impact on sediment loads when many varied practices are placed throughout the watershed remains a challenge. In this study, the impact of conservation practices on erosion from sheet & rill and ephemeral gully sources at field and watershed scales was investigated on a USDA Conservation Effects Assessment Project (CEAP) watershed draining into the Chesapeake Bay using USDA watershed simulation technology. Three separate time periods were evaluated representing before, after, and a transition period to describe when conservation practice conditions were implemented to determine their impact on sediment loads. Results showed that applying a mix of natural riparian vegetative buffers, edge-of-field filter strips, and grassed waterway conservation practices significantly reduced sediment yield and loads by approximately 10% for ephemeral gully and 30% for sheet & rill sources compared to single practices alone. The development of conservation plans when considering the watershed as an integrated system to maximize conservation resources, productivity, competitiveness, and long-term sustainability of farm management operations is key. Soil erosion prediction technology that can be customized to quantify varied and integrated sources and sinks of sediment is one tool in the toolbox to support stakeholders in developing comprehensive mitigation plans.

Technical Abstract: Conservation practices have been recognized as an important mitigation tool to reduce soil loss and sediment transport from agricultural fields. Multiple conservation structures and farming practices have been proposed to target erosional processes with varying results of sediment trapping efficiency. The quantification of their performance at the watershed scale when multiple integrated and spatiotemporal varying processes occur, remains a challenge. In this study, the impact of conservation practices on erosion from sheet/rill and ephemeral gully sources at field and watershed scales were investigated on a USDA Conservation Effects Assessment Project (CEAP) watershed draining into the Chesapeake Bay. Three periods were identified: 1990-2000, 2010-2020, and 2000-2010 representing before, after, and a transition period of conservation practices implementation, respectively. Ephemeral gullies and conservation practices were characterized at raster grid scale and evaluated at field and watershed scales. The AnnAGNPS watershed pollution model was used to quantify sediment loads before and after actual conservation practices were implemented. Simulation results indicated a potential reduction from implemented conservation practices of approximately 10% from ephemeral gully sources and 30% from sheet/rill sources in annual average sediment loads, or by 60% overall when comparing annual averages expressed as sediment concentration. Analysis of sediment loads indicates that the implemented practices are less effective in deterring sediments from ephemeral gully sources. Two significant precipitation events with an estimated recurrence interval greater than 250 years were estimated to be responsible for adding 25% (151.73Mg) to the 11-year annual average sediment load prompting the need for future research on the impact of extreme events on soil loss. Using customized soil erosion prediction technology designed for the quantification of diverse source and sink of sediment is a valuable resource for stakeholders seeking to develop erosion mitigation strategies.